Asahi Kogaku Kogyo Kabushiki Kaisha

Pentax Corporation

Hoya Corporation

Other

Asahi Kogaku Kogyo Kabushiki Kaisha of Tokyo

Suguru Takishima

Isao Okuda

Shimpei Shinozaki

Hiroshi Kanazawa

Hiroshi Yamamoto

Hiroshi Nishikawa

Koichi Maruyama

Takeharu Shin

Toshio Nakagishi

Masato Noguchi

Wataru Kubo

Masahiro Oono

Satoshi Inoue

Takashi Morita

Toshiyuki Kase

Yuta Yoshida

Naoto Hashimoto

Hirotaka Fujii

Hisashi Konno

Shinpei Shinozaki

Akihiro Tanaka

Masahiko Sasaki

Koichiro Nishikawa

Amit Jain

Makoto Iwaki

Hiroshi Kokado

Makoto Iki

Ryoichi Nakanishi

Junichi Takeda

Masami Ninomiya

Ryosei Honma

Hiroshi Motohashi

Osamu Watanabe

An optical information recording/reproducing optical system where resin material has Tg&#x3e;115&#xb0; C., first, second and third films are on an optical disc side of an objective lens and surfaces of an optical element, respectively, a light source side of the objective lens has a fourth film having four or more layers not containing Ti, each of the first, second and third films includes a non-high refractive index layer made of one of silicon oxide, aluminum oxide, aluminum fluoride and magnesium fluoride or a mixture of at least two of them, each of the first, second and third films is not made of one of Ti, Ta, Hf, Zr, Nb, Mo and Cr, a layer of the fourth film closest to a base material is the non-high refractive index layer. The fourth film satisfies 350&#x3c;&#x3bb;&#x3c;420 and 600&#x3c;&#x3bb;&#x3c;750, and reflectivity thereof decreases monotonously.

Optical information recording/reproducing optical system and optical information recording/reproducing apparatus

An optical information recording/reproducing optical system, comprising a light source; an optical element converting a laser beam into a substantially collimated beam; and an objective lens, wherein a wavelength &#x3bb; (unit: nm) of the laser beam falls within a range of 400&#x3c;&#x3bb;&#x3c;410, the optical element and the objective lens are made of same resin materials or different resin materials having a glass transition temperature of Tg&#x3e;115&#xb0; C., each of optical surfaces is configured not to have an optical thin film which contains at least one of or elements of titanium, tantalum, hafnium, zirconium, niobium, molybdenum and chromium, each of optical surfaces of the optical element is provided with an antireflection film made of one of or a mixture of at least two of silicon oxide, aluminum oxide, aluminum fluoride and magnesium fluoride, and a following condition is satisfied 

An objective lens for an optical information recording/reproducing optical system for an optical disc letting a laser beam impinge on a recording layer of the optical disc, and wherein a center wavelength &#x3bb; (unit: nm) of the laser beam is in a range defined by a condition: 390&#x2266;&#x3bb;&#x2266;420, a base material of the objective lens is made of resin, the resin has a glass transition temperature Tg and light transmissivity T (unit: %) per a path length of 3 mm at a wavelength of 406 nm defined by conditions: Tg&#x2267;115&#xb0; C., 85&#x2266;T&#x2266;90, same antireflection films or different types of antireflection films are respectively formed on optical surfaces of the objective lens, and each of the antireflection films formed on the objective lens has a thickness of 100 nm or more in a vicinity of an optical axis of the objective lens.

An optical disk drive for recording information on a recording surface of an optical disk and reading information recorded in the optical disk is provided. The optical disk drive includes a spindle to rotate the optical disk and a carriage movable in parallel with a tracking direction of the optical disk. The carriage includes a laser light source to emit laser light, a collimator lens to convert divergent light into parallel light and is arranged with an optical center thereof being in a farther and offset position with respect to an optical axis of the laser light, a reflecting mirror to receive and deflect the laser light transmitted through the collimator lens in a direction perpendicular to the recording surface of the optical disk, and an objective lens to converge the laser light deflected by the reflecting mirror on a position corresponding to the recording surface of the optical disk.

Optical disk drive

Lens

An optical disc drive includes an optical head having a stationary portion and a movable portion. The movable portion supports an objective lens for converging a beam emitted from the stationary portion on an optical disc. The movable portion moves radially across an optical disc in order to irradiate the beam on a desired track of the optical disc. The optical disc drive is further provided with an aberration correcting lens that corrects aberration caused by the objective lens. The aberration correcting lens is mounted on the movable portion so as to be movable in a direction substantially orthogonal to a movable direction of the movable portion, which may parallel or perpendicular to the optical disc. The aberration correcting lens is moved in accordance with a variation of the aberration caused by the objective lens.

Optical disc drive having a movable aberration correcting lens

There is provided an optical recording media cartridge, which is provided with a case that accommodates the optical recording media and that has an opening, and a shutter that is attached to the case and that is movable between a first position at which the shutter covers the opening and a second position. The optical recording media cartridge is further provided with a shutter lock mechanism that locks the shutter while the shutter is positioned at the first position, and a shutter release mechanism that releases the shutter locked by the shutter lock mechanism by utilizing a magnetic force exerted thereon.

Cartridge for protecting optical recording media

An optical disc apparatus includes a fixed portion having a light source portion and a movable portion that holds an objective lens and moves along a radial direction of an optical disc. The fixed portion includes the light source portion for selectively emitting short and long wavelength laser beams, and a collimator lens for collimating the laser beams. The objective lens includes a positive refractive lens and a diffractive lens structure formed on a surface of the refractive lens. The diffractive lens structure has wavelength dependence such that spherical aberration varies in the undercorrected direction as wavelength of incident light increases. The objective lens converges the short wavelength laser beam of a predetermined diffraction order onto an informatlon layer of a thin cover type optical disc, and converges the long wavelength laser beam of the identical diffraction order onto an information layer of a thick cover type optical disc.

Optical disc apparatus

An optical head includes (1) a stationary optical unit fixed to a body of the optical disk drive, (2) a rotary arm rotatable along a surface of the optical disk, which carries an object lens which converges the light on the optical disk, and (3) a light-introducing system which directs the light from the light source module to the rotary arm so that the light proceeds in the rotary arm to reach the object lens.

Optical head of disk drive

An optical disc drive is provided with a light source unit that emits a collimated light beam, and a carriage mounting an objective lens for converging the collimated light beam on a recording surface of an optical disc. The carriage is movable in a direction traversing data tracks of the optical disc. The optical disc drive is further provided with a lens actuator mounted on the carriage. The lens actuator has a movable unit capable of moving the objective lens in first and second directions, independently. The first direction is a direction of an optical axis of the objective lens, and the second direction is a direction on a plane parallel to the data recording surface of the optical disc. A magnetic head is mounted on the movable unit of the lens actuator. The magnetic head is capable of applying a magnetic field onto the data recording surface of the optical disc when data is to be recorded on the optical disc. A positional relationship between the objective lens and the magnetic head is substantially constant regardless of the moving amount of the movable unit in the first and second directions.

Optical disc drive

A magnetic head up/down mechanism for an magneto-optical disc drive is provided with a magnetic head supporting member mounting a magnetic head. The supporting member is attached to one end of an elongated plate spring member. A moving system is further provided to move the plate spring member together with the supporting member so that the magnetic head is located either an operative position or a retracted position. The operative position and the retracted position are located between an objective lens of the disc drive and the data recording surface of a magneto-optical disc loaded in the magneto-optical disc drive.

Magnetic head up/down mechanism for magneto-optical disc drive

A rectangular shutter leaf is swingably provided to an opening of a front panel of a disk drive device, a cartridge being inserted or discharged through the opening. The shutter leaf is supported to, and swingable about, one side of the shutter leaf. A resilient skirt is provided on all sides of the shutter leaf except the supported side, and extends toward the periphery of the opening. When the shutter leaf is parallel to the front panel and substantially closes the opening, the resilient skirt covers a clearance between the shutter leaf and the opening, preventing the entry of debris or dust into the interior of the disk drive device through the opening.

Shutter mechanism for disk drive device

Growing community of inventors

Tokyo, Japan

Suguru Takishima